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This contribution presents a linear off-diagonal MIMO canceller (ODMC) that aims at mitigating the upstream self far-end cross-talk (FEXT) that severely impacts the performance of very high speed digital subscriber line (VDSL) services at the central office (CO). The ODMC operates per frequency and is thus well suited for DMT-based VDSL systems. We introduce a low complexity and low latency adaptive...
A novel multimodal approach for independent component analysis (ICA) of complex valued frequency domain signals is presented which utilizes video information to provide geometrical description of both the speakers and the microphones. This geometric information, the visual aspect, is incorporated into the initialization of the complex ICA algorithm for each frequency bin, as such, the method is multimodal...
In this paper we present the operation results of a portable computer-based measurement equipment conceived to perform non-destructive testing of suspicious termite infestations. Its signal processing module is based in the Spectral Kurtosis (SK), with the de-noising complement of the Discrete Wavelet Transform (DWT). The SK pattern allows the targeting of alarms and activity signals. The DWT complements...
An optimal pilot assisted detector of OFDM signals in frequency selective fading channels is proposed and investigated. This detector does not estimate the channel explicitly but jointly processes the received data and pilot symbols to recover the data with minimum error. It outperforms the traditional mismatched detectors that treat channel estimates as perfect. We use complex exponential functions...
In many speech separation and enhancement techniques, establishing a statistical model like a Vector Quantization (VQ) is a must to handle the so-called model-based approaches. It is also desirable to establish a trade-off between sparsity and accuracy in the quantizer. To do so, in this paper we present split-VQ for sinusoidal parameters. We observed that sinusoidal parameters including amplitudes...
In this paper, two new noise reduction algorithms are presented which are robust to the mismatch problem commonly exist between the ideal array look direction and actual speaker's Direction-Of-Arrival (DOA). Deriving a set of leakage constraints and incorporating them into the state-of-the-art Generalized Sidelobe Canceller (GSC) algorithm leads to two new noise reduction algorithms, namely Constrained...
In this paper we propose a novel LMS algorithm in combination with a voice activity detector (VAD) for filtering speech sounds in the Adaptive Noise Cancelation (ANC) problem. The filtering stage is based on the minimization of the squared Euclidean norm of the difference weight vector under a stability constraint over the a posteriori estimation error. To this purpose, the Lagrangian methodology...
One of the most common degradations in medical images is their poor contrast quality. This suggests the use of contrast enhancement methods as an attempt to modify the intensity distribution of the image. In this paper, a new edge detected morphological filter is proposed to sharpen digital medical images. This is done by detecting the positions of the edges and then applying a class of morphological...
H.264 is the latest HDTV video compression standard, which provides a significant improvement in coding efficiency at the cost of huge computation complexity. Provided that discrete cosine transform coefficient(DCT) blocks can be quantized to all zeros, the process of transform and quantization on this all-zero block(AZB) can be skipped, which will reduce significant redundant computations. In this...
In multiview video, a number of cameras capture the same scene from different viewpoints. There can be significant variations in the colour of views captured with different cameras, which negatively affects performance when the videos are compressed with inter-view prediction. In this paper, a method is proposed for correcting the colour of multiview video sets as a preprocessing step to compression...
In this paper we consider the problem of deriving an efficient adaptation algorithm when the secondary path of a single-channel feed-forward Active Noise Control (ANC) system contains a memoryless nonlinearity affecting the output of the controller. In order to avoid complex nonlinear adaptation strategies, the solution proposed consists in the design of a predistorter that linearizes the input-output...
A new blind equalization algorithm based on suboptimum Bayesian symbol detector and discrete wavelet network is presented. First, the shortcomings of well-known Bayesian blind equalization is discussed, then the method is modified in order to be used for nonlinear channels. It uses discrete wavelet networks instead of linear models to cover the nonlinearities and guarantee global optimization. It...
To remove signal-dependent noise of a digital color camera, this paper presents a new color-image denoising scheme in a wavelet transform domain, which is newly developed from the classic spatially-adaptive wavelet denoising scheme with the Wiener-type linear shrinkage function. The classic Wiener-type linear shrinkage function works well for monochrome images; to utilize linear inter-channel color...
The paper presents two different multimodal interfaces based on automatic recognition and interpretation of speech and gestures of user's head and hands, developed within the framework of the SIMILAR European Network of Excellence. The architectures of ICANDO and MOWGLI multimodal interfaces, modalities recognition, information synchronization and fusion as well as qualitative comparison and quantitative...
Accurate estimation of glottal closure instants (GCIs) in voiced speech is important for speech analysis applications which benefit from glottal-synchronous processing. Electroglottograph (EGG) recordings give a measure of the electrical conductance of the glottis, providing a signal which is proportional to its contact area. EGG signals contain little noise or distortion, providing a good reference...
Hearing instrument development involves the acoustic verification of system functionality. The used test signals should allow efficient repetition of tests. Synthetic stimuli are therefore proposed as test signals, because they can be tailored to the test objectives. For the purpose of frequency response measurements in digital hearing instruments, we present a synthesis procedure targeted at test...
The knowledge about the number of signals plays a crucial role in array processing. The performance of most direction finding algorithms relies strongly on a correctly specified number of signals. When the number of signals is unknown, conventional approaches apply information theoretic criteria or multiple tests to estimate the number of signals and parameters of interest simultaneously. These methods...
The goal of this project is to research and develop a bio-acoustic automatic detector of a devastating pest attacking palm trees, which has recently appeared in Mediterranean countries. The method is based on piezoelectric sensors that are inserted in the tree trunk and record locomotion and feeding vibrations of the insect. The obtained signals are amplified, filtered, parameterized and automatically...
The idea of applying blind source separation (BSS) algorithms has recently been introduced for noise separation in integrated circuits. Until now, the introduced methods were based on multi-channel BSS. But in many real applications only one mixture is available. Therefore, multi-channel BSS methods are not helpful. In this paper, we propose a new approach to separate individual noise and source signals...
Detection of a compact signal with a given profile mixed with a deterministic background and non-stationary noise is an issue of great interest in many scientific areas. In this paper, we propose a methodology based on filter design, that allows both the removal of the background and the estimation of the signal amplitude. Under certain conditions this filter is a wavelet with several vanishing moments...
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